Yealink SIP-T2 SERIES Administrator's Manual page 962

Administrator's Guide for SIP-T2 Series/T19(P) E2/T4 Series/CP860 IP Phones
This section provides the DSS key parameters you can configure on IP phones. DSS key
consists of line key (line key is not applicable to SIP-T19(P) E2 and CP860 IP phones),
programable key and ext key (ext key is only applicable to SIP-T48G/T46G/T29G/T27P IP
phones).
The following table lists the number of DSS keys you can configure for each phone
model:
Phone Model
SIP VP-T49G
SIP-T48G
SIP-T46G
SIP-T42G
SIP-T41P
SIP-T40P
SIP-T29G
SIP-T27P
SIP-T23P/G
SIP-T21(P) E2
SIP-T19(P) E2
CP860
Note
The programable key takes effect only if the IP phone is idle.
The ext key takes effect only if the expansion module is connected to the IP phone.
940
Line Key Programable Key
29
29 13
27 13
15 11
15 11
3 11
27 14
21 14
3 11
2 11
/ 11
/
Ext Key
7 /
39
39
/
/
/
39
39
/
/
/
8 /